Airborne Antenna Considerations for C-Band Telemetry Systems
By David Farr
The changeover of many test ranges from Sband to C-band telemetry implies the need to modify or replace current systems. Several antenna-related issues need to be considered in to order facilitate a smooth transition to C-band. Amongst these are changes in vehicle-induced pattern degradation, the effect on increased propagation loss on link budgets, and the potential need for multi-band antennas that also support legacy systems during the transition. This Paper discusses these issues for both existing telemetry systems modified for C-band and for new systems. Conformal and nonconformal antennas will be addressed in this discussion.
It is fairly well known within the aerospace community that telemetry is moving from the traditional L-band and S-band frequency ranges up to C-band. It is widely understood that the reason for this push to C-band is twofold. First, traditional L and S-band frequency bands have been greatly reduced through re-allocation for a variety of reasons by different markets and second, bandwidth required for most applications has seen exponential growth. This exponential growth has not only been seen in military applications but in civilian aerospace platforms as well.